130 
BULLETIN OF THE BUREAU OF FISHERIES 
and catfish in Lake Keokuk. Nevertheless, the take of buffalo fish in the upper 
lake in 1922 showed a further increase over that of 1917. The surveys for 1914, 
1917, and 1922 suggested a steady upward trend in the abundance of buffalo fish in 
the region of Lake Pepin, but in 1927 buffalo fish were found in extremely small 
numbers. 
The changes apparent in the catches of bowfin (1,466 per cent increase) and 
catfish (848 per cent increase) in Lake Pepin are not explicable on the basis of any 
conditions possible of association with the dam. In the case of the bowfin the 
increase is most probably attributable to the propaganda conducted by the Bureau 
of Fisheries in 1917 for the greater utilization of this fish in smoked form; thus, 
from Lake Keokuk 26,000 13 pounds were marketed in 1917, whereas none had been 
sold in 1914; and again, none were reported in 1922, but a significant catch appears 
in 1927. There is no dependable market, apparently, for this much condemned fish, 
and the fishery goes by vagary. 
The large catch of catfish and bullheads from Lake Pepin in 1917 may also have 
been associated with the “eat more fish” campaign of war times, but it will be noted 
that even in 1922 the catch was more than four times as great as in 1914 (but only 
twice as great in 1927). Lake Keokuk shows a steady increase in pounds of catfish 
taken up to 1922, the yields for the three years of survey being, respectively, 72,000, 
110,000, and 184,000 pounds (140,000 in 1927). These figures seem consistent with 
the expectation that impounded waters of increased area would be favorable to the 
multiplication and growth of several species of bottom-feeding habit. 
A decline in the catch of drum in Lake Pepin had been observed in the seine 
collections made by the bureau in connection with the propagation of fresh-water 
mussels, and it had been suspected that this might be attributable to the dam; but 
the decline of 10 per cent in commercial catch in that lake from 1914 to 1917 was 
matched by an increase of 498 per cent in Lake Keokuk, which is also above the 
dam. When we examine the figures for 1922 we find a great increase for Lake Pepin 
(234 per cent) but a decline of 59 per cent for Lake Keokuk; the catch of drum in 
Lake Keokuk was still, however, more than twice as great in 1922 as in 1914. In 
both lakes the figures for yield of drum in 1927 are not notably different from those 
of 1914. 
While the capture of “German” carp, the chief product of fishery (in quantity) 
in both lakes had virtually doubled in Lake Pepin in 1917, the increase in Lake Keo- 
kuk was substantially higher, an increment of 152 per cent being observed. In 1922 
the remarkable increase of 452 per cent may be noted for Lake Pepin, while the catch 
in Lake Keokuk fell 64 per cent, having been even smaller than in 1914. Regarding 
the latter lake, reference may be made to previous remarks concerning the buffalo fish. 
The great catch of carp in Lake Pepin in 1922 undoubtedly was due to a notable 
natural phenomenon, which is discussed in another place. (Coker, 1930). The 
catch in 1927, while much smaller than in the years about 1922, was still much larger 
than in 1914 or 1917. In Lake Keokuk the change from 1922 to 1927, as regards the 
carp, was not significant. The large catch of 1917, for reasons to be mentioned later 
(Coker, 1930), was due, perhaps, to special conditions. 
The quillback or “white carp,” on the other hand, shows first a marked decline 
in Lake Pepin, the catch in 1917 (14,000 pounds) being about one-fourth the catch 
of 1914 (61,000 pounds), with a partial recovery in 1922 (47,000 pounds) and an ex- 
13 In the text, figures are given in round numbers in nearly all cases. Exact figures may be found in the tables. 
